Refactor user_to_num_current_syncs from both worker and presence writ…

…er versions of the handler onto the base

synapse/handlers/presence.py

@@ -154,6 +154,10 @@ def __init__(self, hs: "HomeServer"):
 
         self._busy_presence_enabled = hs.config.experimental.msc3026_enabled
 
+        # The number of *ongoing* syncs on this process, by user id. Empty if
+        # use_presence is false. While this is non zero a user will never go offline.
+        self._user_to_num_current_syncs: Dict[str, int] = {}
+
         active_presence = self.store.take_presence_startup_info()
         self.user_to_current_state = {state.user_id: state for state in active_presence}
 
@@ -413,10 +417,6 @@ def __init__(self, hs: "HomeServer"):
             hs.config.worker.writers.presence,
         )
 
-        # The number of ongoing syncs on this process, by user id.
-        # Empty if _presence_enabled is false.
-        self._user_to_num_current_syncs: Dict[str, int] = {}
-
         self.notifier = hs.get_notifier()
         self.instance_id = hs.get_instance_id()
 
@@ -545,8 +545,8 @@ async def user_syncing(
             self.mark_as_coming_online(user_id)
 
         def _end() -> None:
-            # We check that the user_id is in user_to_num_current_syncs because
-            # user_to_num_current_syncs may have been cleared if we are
+            # We check that the user_id is in _user_to_num_current_syncs because
+            # _user_to_num_current_syncs may have been cleared if we are
             # shutting down.
             if user_id in self._user_to_num_current_syncs:
                 self._user_to_num_current_syncs[user_id] -= 1
@@ -751,10 +751,6 @@ def __init__(self, hs: "HomeServer"):
 
         self._next_serial = 1
 
-        # Keeps track of the number of *ongoing* syncs on this process. While
-        # this is non zero a user will never go offline.
-        self.user_to_num_current_syncs: Dict[str, int] = {}
-
         # Keeps track of the number of *ongoing* syncs on other processes.
         # While any sync is ongoing on another process the user will never
         # go offline.
@@ -984,7 +980,7 @@ async def _handle_timeouts(self) -> None:
 
         syncing_user_ids = {
             user_id
-            for user_id, count in self.user_to_num_current_syncs.items()
+            for user_id, count in self._user_to_num_current_syncs.items()
             if count
         }
         for user_ids in self.external_process_to_current_syncs.values():
@@ -1051,8 +1047,8 @@ async def user_syncing(
             affect_presence = False
 
         if affect_presence:
-            curr_sync = self.user_to_num_current_syncs.get(user_id, 0) + 1
-            self.user_to_num_current_syncs[user_id] = curr_sync
+            curr_sync = self._user_to_num_current_syncs.get(user_id, 0) + 1
+            self._user_to_num_current_syncs[user_id] = curr_sync
 
             prev_state = await self.current_state_for_user(user_id)
 
@@ -1095,7 +1091,7 @@ async def user_syncing(
 
         async def _end() -> None:
             try:
-                self.user_to_num_current_syncs[user_id] -= 1
+                self._user_to_num_current_syncs[user_id] -= 1
 
                 prev_state_inner = await self.current_state_for_user(user_id)
                 await self._update_states(